Virtual hand being controlled by the monkey's brain activity to choose the correct object/texture based on electrical signals (Source: Duke Center for Neuroengineering)

A virtual game allows monkeys to control an avatar hand and make correct choices between textured objects with only brain activity

Duke University researchers have taught monkeys to control a virtual hand using nothing but their brain activity in an effort to create technologies that can aid people who are severely paralyzed.

Miguel Nicolelis, M.D., Ph.D., study leader and professor of neurobiology at Duke University Medical Center, and a team of Duke researchers have created a virtual game that allows monkeys to control an avatar hand and make correct choices with only brain activity.

The game consists of three virtual objects that are identical in appearance. A virtual hand is on the screen to identify which object the controller is currently "touching." Using only brain activity and no other part of their body's, trained monkeys controlled the virtual hand to explore each of the objects. Each object is of a different texture, which is conveyed to the monkeys through different, assigned electrical signals associated with each one, which are transmitted to the monkeys when the hand is placed on them in the game.

The monkeys were able to learn which electrical response corresponded with each of the three objects' textures, learning to differentiate each one upon "touch." One monkey attempted the task nine times before learning to choose the correct object while another only needed four attempts. According to researchers, the monkeys began sensing the correct object instead of randomly selecting objects after awhile.

"This is the first demonstration of a brain-machine-brain interface that establishes a direct, bidirectional link between a brain and a virtual body," said Nicolelis. "In this BMBI, the virtual body is controlled directly by the animal's brain activity, while its virtual hand generates tactile feedback information that is signaled via direct electrical microstimulation of another region of the animal's cortex.

"This is also the first time we've observed a brain controlling a virtual arm that explores objects while the brain simultaneously receives electrical feedback signals that describe the fine texture of objects 'touched' by the monkey's newly acquired virtual hand.”

The study's conclusions suggest that if monkeys can pull this off, humans easily can as well in the future. Researchers hope this eventually leads to a robotic exoskeleton for patients who are severely paralyzed, which will allow them to move and feel the world around them once again.